Article assembling fixture



Sept. 13, 1938. s PlKE 2,129,869

ARTICLE ASSEMBLING FIXTURE Filed June 27, 1936 FIG.

ATTORA/f) Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE 2,129,869 ARTICLE ASSEMBLING FIXTURE- Application June 27, 1936, Serial No. 87,694

6 Claims.

This invention relates to article assembling fixtures, and more particularly to fixtures for clamping and holding contact spring assemblies of relays under a desired pressure during the securing thereof.

An object of the invention is to provide a simple, practical and efficient fixture for use in assembling and securing a plurality of elements under a desired pressure to form an article.

In accordance with the aforementioned object, this invention contemplates in one embodiment thereof a fixture for clamping and holding contact spring assemblies, or pile-ups, of relays, or other electrical devices, under a desired pressure to obtain a maximum tightness of retaining screws.

Specifically a fixture embodying the features of this invention comprises a frame having a yieldably and slidably mounted carriage supporting a beam intermediate the ends of which is a clamping head aligned with a stationary companion head on the frame, between which heads a spring pile-up may be gripped. A cam on the carriage with its peripheral cam face constantly bearing on one side of a finger pivotally carried on the frame may be rotated by a hand wheel to slide the carriage to permit inserting the spring pile-up between and thereafter close the heads upon the pile-up and exerting sufiicient pressure to take up all looseness in the fixture parts. An eccentric cam with its peripheral cam face constantly bearing on the other side of the finger is rotated by a hand lever to move the cam and carriage to further compress the spring pile-up until the desired pressure is reached. Operatively associated with the beam is a gauge that indicates the pressurebeing applied between the clamping heads by the deflection of the beam. Apertures are provided in the stationary clamping head for 40 guiding a screw driver blade to the heads of the spring pile-up retaining screws, which are tightened to a maximum while the desired pressure is maintained, the opposite clamping head being provided with depressions for receiving the inner 45 ends of the screws.

Other features and advantages of this invention will more fully appear from the following detailed description taken in connection with the accompanying drawing, wherein 50 Fig. 1 is a plan View of a clamping fixture embodying the features of this invention with a relay contact spring pile-up, shown in broken outline in position while under compression;

Fig. 2 is a fragmentary longitudinal vertical section taken on the line 22 of Fig. 1;

Fig. 3 is a detail vertical section on an enlarged scale taken on the line 33 of Fig. 1, and

Fig. 4 is a vertical section taken on the.line 4-4 of Fig. 3.

Referring particularly to Figs. 1 and 2, a base,

or frame of the fixture, is indicated at IE2, provided with integral aligned apertured bearings H on opposite sides in which are reciprocably carried rods 12, which at one end are secured, as indicated at l3, to a carriage M, the carriage being provided with integral aligned apertured lugs l5 for the reception of the rods. Journaled in aligned spaced bearings on the carriage M at its left end is a transversely extending shaft it to which is secured intermediate the bearings a cam 19, the shaft at opposite ends being equipped with hand wheels whereby the cam may be rotated by an operator from either side of the fixture. An eccentric cam 2i fixed to a transversely extending shaft 22 journaled in aligned spaced bearings on the frame Ml is arranged at the left of the cam l5 the peripheral cam faces of the cams being spaced from contact with each other by an interposed finger 2 2 pivoted between embossments 25 on the frame it at 26 (Fig. 2). The finger 24 serves to prevent the peripheral faces of the cams from rolling on each other during adjustment thereof, to be described hereinafter, which rolling contact of one or the other of the cams on the other would tend to disturb the adjustment thereof. Attached to opposite ends of the shaft 22 are hand levers 21 whereby the operator may rotate the eccentric cam El from either side of the fixture, the levers and the frame It] being provided with cooperating stop surfaces 28 (Fig. 2) for limiting the movement of the levers in either direction. A friction ring 29 is provided between the inner face of the hub of each of the levers 21. and the adjacent surface of the frame 10 which are effective to maintain the levers in any adjusted position.

Surrounding each of the reciprocable rods 12 and bearing at opposite ends against an adjustable collar 30 on the rod and the end face of the right hand bearing i I is a compression spring 3!. The spring 3i normally acts to move the carriage M towards the left, the finger 2 and the cam H on the frame 10 serving as a stop means. Upon its right end vertical face the carriage M is provided with four horizontally extending aligned bifurcations 32 uniformly spaced at each side of the longitudinal center line of the fixture, and fitting closely between the furcations of which is a steel beam 33. t each end, the beam is engaged by the collar 36 on the adjacent rod 12 which serves to lock the beam against an inner wall 34 (Fig. 1) of each of the end bifurcations 32, the beam, it will be noted, (Fig. 1) not resting against the corresponding walls of the center pair of bifurcations which are cut slightly further back than the end bifurcations.

A shouldered clamping head 35 bifurcated at its inner end 36 is removably secured, at a point intermediate the center pair of bifurcations 32, on the carriage I4, to the beam 33 by set screws 39 threaded into the furcations and set against opposite faces of the beam, the furcations being slidably fitted in the space between the center pair of bifurcations 32 to prevent longitudinal movement of the beam on the carriage, but permitting slight longitudinal movement of the clamping head relative to the carriage when the beam is deflected during a compressing action to be presently described. Removably secured by set screws 40 in the right end wall of the frame I 0 is a stationary shouldered clamping head 4| which is aligned with the clamping head mounted on the carriage I4. Formed in the head 4| are two vertically aligned apertures 42 which extend from the inner end to a depressed rectangular shaped surface 43 at its outer end, opposite the outer end of the head 35. The outer end of the clamping head 35 is provided with two depressions 46 which are aligned with the apertures 42 of the head 4|. The purpose of the apertures 42 and depressed surface 43 of the head 4| and the depressions 46 of the head 35 will be described hereinafter. The clamping heads are readily removable whereby other heads adapted to clamp therebetween spring pile-ups for various designs of relays may be accommodated.

Secured to the right end wall of the carriage I4 is an indicator gauge 41, an integral projecting sleeve 48 thereof being entered in an aperture in the carriage wall and secured in position by a set screw 49 Fig. 3. A spring pressed stem 5|] of the gauge 4'! extends from the outer end of the sleeve 48 and bears against the left vertical surface of the beam' 33. It will be observed, referring to Figs. 2 and 3, that the cam shafts 22 and H3, gauge stem 50, beam 33 and the clamping heads 35 and 4| are all disposed on a common horizontal center line. The spring pressed stem of the indicator gauge is operatively connected to an indicator hand 53 of the gauge which as the beam is defiected, in the operation of the fixture, moves over a graduated dial of the gauge which has indicia 54 thereon representing fractions of an inch. Pound pressures corresponding to the gauge readings for the convenience of the operator are indicated on a plate 55 secured to the upper surface of the right end wall of the carriage M, or they may be indicated directly on the gauge dial.

A description of the operation of clamping under a desired pressure, a contact spring assembly or pile-up and holding the pressure to obtain the maximum tightness of retaining screws for the pile-up is as follows:

As shown in Fig. 3 a relay spring pile-up 56, of a relay 5'! (Figs. 1 and 2), shown in broken outline is in position between the clamping heads 35 and 4| and is being subjected to the desired pressure. In the normal posititon of the elements of the fixture the hand levers 21 are in a backward position, as shown in fragmentary broken outline (Fig. 2), wherein the high point of the eccentric cam 2| will be rotated to a position wherein no pressure is being exerted on the cam l9 through the interposed finger 24 to slide the carriage M to the right to compress the pile-up 56 between the heads 35 and 4|. Also in the normal position the cam I9 by means of the hand wheels 20 will be rotated counter-clockwise to permit the springs 3| to act whereby the carriage I4 is moved to the left upon the frame In to provide a suitable space between the heads 35 and 4| to receive a spring pile-up 56 therebetween.

Assuming the parts are in their normal positions, as described, the spring pile-up 56 is positioned by an operator between the clamping heads 35 and 4| with the heads of a pair of retaining screws 60 facing toward the right and entered into the left ends of the apertures 42 of the stationary head 4|, the apertures being vertically aligned as clearly shown in Fig. 3. With the entering of the heads of the screws 60, which are not drawn up tight in the pile-up, into the apertures 42 a rectangular shaped washer plate 6| behind the heads of the screws engages the depressed rectangular shaped surface 43 of the head 4|, as shown in Fig. 3, the surface being slightly larger than the plate. The surface 43 serves as a stop surface for the pile-up 56 during the clamping action of the fixture and being depressed, also serves as a centering guide for positioning the pile-up against the head 4|.

While holding the pile-up 56 in the described position against the head 4| the operator slides the carriage |4 towards the right by rotating the cam l9 clockwise by means of one or the other of the hand wheels 20, the high point of the cam being advanced toward the pivotal finger 24 and the eccentric cam l9 which serves as stop means causes the carriage to move upon the frame |0 against the action of the springs 3|. The clamping head 35 is thus moved towards the right and closes the space between the left end of the pileup and the right end of the head, the projecting ends of the retaining screws 60 entering the aligned depressions 46 in the head. A plate 62 similar to the plate 6| is provided at the opposite side of the pile-up and into which the screws 60 are threaded abutting the end of the head 35, as shown in Fig. 3. The cam 9 is rotated in the manner just described to cause sufficient pressure upon the pile-up 56 to take up all looseness in the fixture parts. The pile-up is now clamped between the heads and is ready to receive the desired pressure which is effected by the operator pulling the levers 21 forward from the dotted outline position to the full line position shown in Fig. 2. It is to be understood that the forward position of the levers will vary with the thickness of the particular pile-up between the heads. As the levers are drawn forward the high point of the eccentric cam 2| is advanced clockwise toward the pivotal finger 24 interposed between the cams l9 and 2|, thus causing the carriage l4 to move toward the right and further compressing the pile-up between the heads.

As the carriage |4 moves toward the right the head 35 also moves therewith, since it is secured to the steel beam 33, which at its ends engages the walls 34 of the end bifurcations 32 of the carriage. The movement of the head compresses the pile-up and the resistance offered to the movement of the head deflects the beam and the amount of deflection thereof causes the spring pressed gauge stem 50 bearing against the left vertical surface of the beam to move slightly to the left, as viewed in the drawing, the movement being transmitted to the indicator hand 53 which in cooperation with the indicia 54 registers the movement in fractions of an inch. When the hand registers with the correct fraction of an inch on the indicia corresponding to the desired pound pressure to which the pile-up should be subjected, which may be read from the gauge dial or the plate 55, the operator 'ceases pulling the levers forward and the parts of the fixture remain in their operated positions with the pressure maintained on the pile-up.

The pile-up retaining screws 60 are then tightened by inserting the blade of a screw driver 65, shown fragmentarily in Fig. 3, successively into the guiding apertures 42 in the clamping head ii to operatively engage the screw heads, the screws then being drawn tight to hold the desired. pressure on the pile-up. The clamping action of the heads upon the pile-up is then released by returning the levers to their backward position (dotted outline Fig. 2), thereby moving the high point of the eccentric cam 2! from its advanced position, the finger 2Q maintaining its engagements with the cams 2i and [9 as the springs 3| act to slide the carriage i i to the left. Thereafter the cam I9 is rotated counter-clockwise by means of the hand wheels 20, the high point of the cam being moved from its advanced position, and the carriage H5 is moved further to the left to permit the removal of the compressed Spring pile-up from the separated clamping heads 35 and M. Thereafter the second pile-up of the particular relay illustrated is clamped and the screws tightened in a similar manner.

As shown in Figs. 3 and 4, an insulator sleeve 66 surrounds the retaining screw Bil of the contact spring pile-up for the purpose of preventing short circuiting between the screw and the contact springs. The sleeve 65 may be composed of hard rubber, or other suitable material, and is of such a length that when the pile-up has been compressed to the desired degree the ends of the sleeve will abut the inner faces of the pile-up washer plates 6! and 62 without being subjected to deleterious pressure. As an alternative the insulator sleeve may be composed of semi-hard rubber or other suitable material, which has an initial length slightly greater than the distance between the inner faces of the washer plates 6! and 62 upon completion of the compressing operation. During the compressing operation the excess material of the semi-hard rubber sleeve flows into small interstices in the pile-up along the periphery of the sleeve.

From the above description it is apparent that a clamping fixture embodying the features of this invention is very simple and efi'lcient, and may be readily and conveniently adapted for clamping and holding under a desired pressure contact spring assemblies of various types of electrical devices during the securing thereof.

Although only one specific embodiment and application of the invention has been shown and described herein, it should be understood that the fixture is capable of other modifications and adaptations without departing from the spirit and scope of the appended claims.

What is claimed is:

1. In a fixture for assembling a plurality of elements, a pair of clamping members, a plurality of rotary cam members, means for rotating one of the cam members to produce a relative movement of the clamping members to engage an assembly of elements placed therebetween, movable means interposed between and abutting the opposedv peripheral cam faces of said cam members, and means for rotating another of the cam members to cause a further relative movement of the clamping members to compress the assembly therebetween.

2. In a fixture for assembling a plurality of elements under a desired pressure, movable and stationary clamping members, rotary cam members, one of said cam members being bodily movable with said movable member and operatively associated with said other cam member which is axially fixed with respect to said stationary member, means for actuating said bodily movable cam member and thereby said movable member to clamp an assembly against said stationary member, said other cam member being effective as an abutment stop, means for actuating said latter cam member to cause further movement of said bodily movable cam member and thereby said movable member to apply additional pressure to the assembly, and means responsive to the movement of said movable member during the application of pressure to the assembly for indicating the amount of pressure applied.

3. In a fixture for assembling a plurality of elements under a desired pressure, movable and stationary clamping members, rotary cam members, a movable finger interposed between and constantly abutting the opposed peripheral cam faces of said cam members, one of said cam members being bodily movable with said movable member, said other cam member being axially fixed with respect to said stationary member,

means for actuating said bodily movable cam member and thereby said movable member to clamp an assembly against said stationary member, said other cam member being effective as an abutment stop, means for actuating said latter cam member to cause further movement of said bodily movable cam member and thereby said movable member to apply additional pressure to the assembly, and means responsiveto the movement of said movable member during the application of pressure to the assembly for indicating the amount of pressure applied.

4. In a fixture for clamping and holding a plurality of elements under a desired pressure while retaining screws are tightened, movable and stationary clamping members, said stationary memher being provided with apertures for receiving slotted heads of retaining screws and permitting the engagement of a screw driver therewith while the elements are under pressure, and means including a plurality of rotary cams, one of which is mounted for movement with the movable member, for actuating said movable member to clamp the elements under pressure against said stationary member and maintaining the pressure while the retaining screws are tightened.

5. In a fixture for clamping and holding elements of a spring pile-up under a desired pressure while retaining screws are tightened, movable and stationary clamping members, said stationary member being provided with apertures for receiving slotted heads of retaining screws and permitting the engagement of a screw driver therewith while the pile-up is under pressure, means including a plurality of rotary cams, one of which is mounted for movement with the movable mem-- ber, for actuating said movable member to clamp the pile-up under pressure against said stationary member, and means responsive to the movement of said movable member during the application of pressure to the pile-up for indicating the amount of pressure applied, said actuating means effective to maintain the pressure applied while the retaining screws are tightened.

6. In a fixture for assembling a plurality of elements, a pair of clamping elements, a bodily movable deflectib-le beam supporting one of the members, means including a rotary cam bodily movable with the beam and effective upon rotation for moving the beam and the member supported thereby to clamp an assembly of elements between the members, and means responsive to the deflection of the beam for indicating the amount of pressure applied to the assembly.

HAROLD S. PIKE. 

